Mobile Stations (MS), handheld devices, Base Stations (BS), Access Points (AP) and other devices of wireless communication systems may include transmitters to transmit Radio Frequency (RF) signals. The transmitters may be linear transmitters, outphasing transmitters, and the like. Transmitters that are used to transmit continuous phase modulation signals, such as, for example, Gaussian Minimum Shift Keying (GMSK) signals, and the like, may combine a linear amplification technique using non-linear components (LINC) with direct modulation through one or more modulation paths that may include fractional-N synthesizers with built in data modulators and power amplifiers. Combination of the modulated, amplified signals may be implemented by a quarter wave combiner, Wilkinson combiner, reactive termination combiner and the like. Alignment of the phases of the amplified outputs to be combined may be important because even minor phase misalignment may lead to reduced efficiency of the transmitter, and may also result in a non-monotonic response that may degrade a desired linearity of the modulation process.
It will be appreciated that for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements.